/* Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.activiti.engine.impl.cmd;

import org.activiti.engine.ActivitiIllegalArgumentException;
import org.activiti.engine.impl.interceptor.CommandContext;
import org.activiti.engine.impl.persistence.entity.TaskEntity;
import org.activiti.engine.task.IdentityLinkType;


/**
 * @author Joram Barrez
 */
public class AddIdentityLinkCmd extends NeedsActiveTaskCmd<Void> {

    private static final long serialVersionUID = 1L;

    protected String userId;

    protected String groupId;

    protected String type;

    public AddIdentityLinkCmd(String taskId, String userId, String groupId, String type) {
        super(taskId);
        validateParams(userId, groupId, type, taskId);
        this.taskId = taskId;
        this.userId = userId;
        this.groupId = groupId;
        this.type = type;
    }

    protected void validateParams(String userId, String groupId, String type, String taskId) {
        if (taskId == null) {
            throw new ActivitiIllegalArgumentException("taskId is null");
        }

        if (type == null) {
            throw new ActivitiIllegalArgumentException("type is required when adding a new task identity link");
        }

        // Special treatment for assignee, group cannot be used an userId may be null
        if (IdentityLinkType.ASSIGNEE.equals(type)) {
            if (groupId != null) {
                throw new ActivitiIllegalArgumentException("Incompatible usage: cannot use ASSIGNEE"
                        + " together with a groupId");
            }
        } else {
            if (userId == null && groupId == null) {
                throw new ActivitiIllegalArgumentException("userId and groupId cannot both be null");
            }
        }
    }

    protected Void execute(CommandContext commandContext, TaskEntity task) {

        boolean assignedToNoOne = false;
        if (IdentityLinkType.ASSIGNEE.equals(type)) {
            task.setAssignee(userId, true, true);
            assignedToNoOne = userId == null;
        } else if (IdentityLinkType.OWNER.equals(type)) {
            task.setOwner(userId, true);
        } else {
            task.addIdentityLink(userId, groupId, type);
        }

        if (assignedToNoOne) {
            // ACT-1317: Special handling when assignee is set to NULL, a CommentEntity notifying of assignee-delete should be created
            commandContext.getHistoryManager().createIdentityLinkComment(taskId, userId, groupId, type, false, true);
        } else {
            commandContext.getHistoryManager().createIdentityLinkComment(taskId, userId, groupId, type, true);
        }

        return null;
    }

}
